A new genus, and new fungal species of the Scutellosporaceae (Gigasporales), named Bulbospora minima, was found in the National Park Vale do Catimbau, located within the semi-arid ‘dry white savanna forest’ biome, called ‘Caatinga’, in Northeastern Brazil. The fungus resembles Orbispora pernambucana since it forms triple walled spores on sporogenous cells (= bulbi, suspensors), and a mono-lobed, hyaline to rarely light yellow germination orb on the inner, germination wall. However, the small spores and the size of the sporogenous cells (62–95 × 58–87 and 18–26 × 13–22 µm, respectively) render this fungus unique within the Gigasporales, since no other species of this order differentiates consistently spores < 100 µm and sporogenic cells < 25 µm in diameter. Phylogenetically, the new fungus forms an ancestral gigasporalean clade next to the Orbispora and Scutellospora, which supports the placement of the fungus into the new genus Bulbospora, and into the Scutellosporaceae. It is the tenth Gigasporales species described during the last decade from NE Brazil, suggesting that this tropical region is a ‘hot-spot’ of gigasporalean biodiversity.